Display screen or portion thereof with a score leaderboard graphical user interface



FIG. 1 is a front view of a display screen or portion thereof with a score leadership graphical user interface showing our design; and,

FIG. 2 is a front view of a second embodiment thereof.

The broken line showing of a display screen with graphical user interface is included for the purpose of showing portions of the article which form no part of the claim. 

CLAIM We claim the ornamental design for a display screen or portion thereof with a score leaderboard graphical user interface, as shown and described. 